Sewing machine



Jan. 17, 1956 w. A. AYRES SEWING MACHINE Filed Jan. 25, 1954 "mm 5 36INVEN TOR. .95 3.9 38

United States Patent SEWING MACHINE Waldemar A. Ayres, Lakewood, Ohio,assignor to White Sewing Machine Corporation, Lakewood, Ohio, acorporation of Delaware This invention relates to a sewing machine andmore particularly to the rotary hook or loop taker mechanism for such amachine.

Ordinary rotary loop takers or hooks include a rotatable cup-shaped bodywhich has a loop seizing beak for manipulating the loop in the upper or:needle thread. The rotary loop taker or hook is located beneath the bedplate of the sewing machine in a location :so that the loop seizingbeak. engages the loop of the upper thread when the reciprocating needlehas passed through the material being sewed and is beneath the bedplate.

The usual construction includes a bobbin case carrier mounted within thecup-shaped body butheld against rotation therewith or therein and whichcarrier receives the bobbin case that contains the lower thread bobbin.Suitable means usually carried by the bed plate of the sewing machinecooperates with a portion of the bobbin case carrier to hold the latter,the bobbin case and bobbin against rotation while the rotary hook orloop. taker rotates relative thereto.

Usually the body of the rotary hook is provided with a circular racewayfor a peripheral bearing rib on the non-rotatable bobbin case carrier.The body usually has a portion cut away .to form the loop seizing beakand to provide also an opening for the upper or needle loop thread topermit the passage of that side of the loop which is carried to theopposite side of the bobbin case carrier.

The bobbin case carrier usually has a portion of its periphery cut awayto provide a similar opening, wherefore the raceway in the body and thebearing rib on the bobbin case carrier are not continuous throughouttheir circumferences.

In the usual constructions gaps are provided in the cooperating bearingsurfaces of the rib and raceway and these gaps can cause what is knownas fcloggingf This clogging may cause serious ,difiicultyin theeflicient operation of a sewing machine of this type and can result intemporarily stopping the operation thereof. Clogging will not occur ifthe upper or needle thread loop is properly or normally formed and theloop seizing beak carries such loop in the correct manner around thebobbin case and bobbin casecarrier. On the other band, should the upperor needle thread loop be improperly formed as, for example, if it shouldbe too slack or if loose threads should accumulate in the vicinity ofthe loop taker such improperly formed loop or loose threads may bepicked up by the loop seizing beak or hook and be drawn between 'theraceway and the body and the peripheral bearing rib on the bobbin case.Under such circumstances it frequently happens that the thread which isimproperly drawn into the raceway becomes so tightly wedged therein asto prevent the free and efiicient operation of the loop taker or even tocompletely stop its operation. When such an occurrence takes place it isnecessary usuallyto take the loop taker apart so that the wedged 'threadcan be removed from the raceway. This is a serious disadvantage astaking the 2,730,978 Patented Jan. 17, 1956 loop taker :apart ordinarilyis a fairly complicated manipulation which the usual "operator is notcompetent to perform and does not ordinarily have the proper tools forthis purpose.

The arrangements heretofore used in loop takers for detachably securingthe bobbin case carrier in the rotary body have been extremelycomplicated and are'difiicult to manipulate in assembling anddisassembling the mechamsm.

An object of the present invention is to provide an improved and novelrotary hook or loop taker mechanism .for a sewing machine which can bereadily assembled and disassembled by the ordinary operator and whichdoes not require special tools for such operations thus enablingtheoperator to readily disassemble and reassemble the mechanism ifnecessary to clear clogging or for other reasons.

Another object of the invention is to provide an improved and novelrotary hook or loop taker mechanism for a sewing machine wherein thenecessity for using both a bobbin case and bobbin case carrier iseliminated and the lower thread bobbin can be mounted directly in themember that usually would be a bobbin case carrier.

Further and additional objects and advantages not hereinbefore referredto will become apparent hereinafter during the detailed description ofan embodiment of the invention which is to follow and which embodimentis illustrated in the accompanying drawings forming a part of thisspecification and wherein,

Fig. l is a plan view on an enlarged scale of a rotary hook or looptaker mounted in a supporting portion of a sewing machine beneath thebed plate.

Fig. 2 is a sectional view taken substantially on line 2-2 of Fig. 1looking in the direction of the arrows.

Fig. 3 is a partial sectional and partial elevational View takensubstantially on irregular line 3-3 of Fig. 1 looking in the direction.of the arrows with the supporting portion of the sewing machineomitted.

Fig. 4 is a detached elevational view of the rotary hook body.

Fig. 5 is a detached plan view of the retainer ring, and

Fig. 6 is a side elevational view of the ring shown in Fig. 5.

Referring to the accompanying drawing, and particularly to Figs. 1 and.2 thereof, it will be understood that a supporting bracket portion ofthe sewing machine is indicated at 10 and that this portion is locatedbeneath the bed plate of the sewing machine and includes a horizontalarm 11 that underlies the hand hole cover plate of the bed plate andwhich is located adjacent to but laterally of the path of movement ofthe vertically reciprocating needle of the sewing machine, all as iswell understood in the art.

The horizontal portion 11 is provided on its upper side with an enlargedcounterbore 12 which is concentric to and communicates with two smallercounterbores of stepped size, in turn, communicating with a short boresmaller in diameter than any of the counterbores. A hearing bushing 13has a pressed fit in the stepped counterbores that communicate with thecounterbore 12 and the larger end of the bearing bushing 13 extendsslightly above the bottom of the counterbore 12.

The body of the rotary hook or loop taker mechanism comprises a circularcup-shaped portion 14 from which extends centrally of the bottom of thecup-shaped por tion a shaft 15 which is either integral with or rigidlyconnected to the cup-shaped portion 14.

The body is mounted in the support 11, with the portion 14 thereoflocated in the counterbore 12 and bearing against the upper and largerend of the bearing bushing 13. The body portion .14 is of such size thatit can freely rotate within the counterbore and is supported by thebearing bushing 13.

The shaft of the body extends downwardly through the bearing bushing 13andfhas fixed to it a collar 16 located in the bore of the bracketportion and acting .to maintain the body against axial displacementsince the bottom of the portion 14 is held against the larger end of thebearing bushing 13 while .the collar 16 engages the smaller end of saidbushing. The shaft 15 extends below the horizontal portion 11 of thebracket portion and is shown as having fixed thereto a bevel gear 17which meshes with a bevel gear 18 that is fixed to a horizontallyextending feed mechanism operating shaft 19, as will be well understoodin the art.

The gear ratio is illustrated as imparting two complete revolutions tothe body of the rotary hook mechanism for each complete revolution ofthe shaft 19 as will be well understood. It will be appreciated that theparticular gear train operatively interconnecting the rotary hookmechanism with the shaft 19 shown in the drawing is for purposes ofillustration and that other types of gear trains for this purpose mightbe employed.

The cup-shaped portion 14 of the body has its side wail cutaway for aportion of its length as indicated at 20 and is provided adjacent thecutaway part 26 witha loop engaging hook or beak 21 that extendscircumferentially of the body and which as the latter rotatescounterclockwise will engage the loop of the upper thread as the needlemoves through the material and below the bed plate during itsreciprocation and passes into the needle opening 22 formed in thehorizontal portion 11 of. the bracket, see Figs. 1 and 2.

The cup-shaped body portion 14 is provided internally with an annularshoulder 23 which constitutes a bearing support for the combined bobbincase carrier and bobbin case which will later be described and hereafterwill be referred to as the bobbin case.

The wall of the cup-shaped portion 14 of the body above the shoulder 23and adjacent the outer end of the wall is provided with an annulargroove 24 for a. purpose later to be described and which shoulder andgroove extend the major portion of the circumference of the or slot31.for the lower thread from the bobbin that is mounted in the bobbinholder or case, all as will be well understood in the art. In addition,the Wall 29 has fixed thereto an angle bracket 32, the horizontal arm ofwhich projects outwardly of the circumference of the wall and beyond thebody and engages in a recess 33 formed in the horizontal portion 11 ofthe bracket and adjacent to the needle opening 22 therein. 7 a

The bracket 32 and recess 33 in which it engages function to hold thebobbin case or holder against rotation while the body of the rotary hookmechanism rotates relative thereto, it being recalled that the holder orcase is supported by the bearing rib 23 of the cup-shaped portion of thebody.

The upstanding circular wall 29 has secured to it on its outer side a.thread guiding lug 34 which is usual and which acts to facilitate thepassage of the thread over the rotary hook mechanism all as will be wellunderstood. The bobbin holder or case is maintained in proper assembledrelationship within the cup-shaped portion 14 of the body of the rotaryhook by the simple and novel means now to be described and which meanscan be readily manipulated by the operator without the necessity ofutilizing special tools or the like.

The means referred to comprises a split circular retaining ring 35 andsaid ring is flat and will be located on the fiat annular shoulderprovided radially outwardly of the reduced diameter upstanding circularwall 29 of the bobbin holder or case by the flange 28 as clearlyindicated in the body portion 1.4 except of course for that part of thecircumference represented by the hook 21 and the cutaway portion 20. j II The outer or free end of the side wall of the body portion 14 atpoints circularly spaced thereof is provided with circularly elongatedopenings 25 and 2b which communicate With the groove 24 with the opening25 located closely adjacent to one end of the groove while the opening26 is located inwardly a substantial distance of the other end of thegroove.

' The bobbin holder or case (the combined bobbin case carrier and bobbincase or holder) comprises a cup-shaped portion 27 which has a somewhatconical exterior configuration and merges into an annular outstandingbearing rib 28 which when the holder or case is mounted in thecup-shaped portion 14 of the body engages and is supported by thebearing rib 23, it being noted that the bottom of the portion 27 of thebobbin holder or case does not contact the bottom of the cup-shapedportion 14 of the body but that clearance is provided therebetween forthe purpose of allowing the lower thread to pass between the'body andthe holder or case.

The holder or case above the flange 23 is provided with an upstandingcylindrical wall 29 of reduced diameter which extends above thecup-shaped portion 14 of the body and above the upper side of thehorizontal portion 11 of the bracket. The cylindrical wall 29 mounts atensioning member 3b as will be Well understood in the art and whichmember is illustrated as similar to the tensioning member shown in mycopending application Serial No. 246,437, filed September 13, 1951, andhence need not be further described herein.

The upstanding wall 29 is also provided with an opening drawings, andparticularly in Figs. 1 and 3.

The rotary ring adjacent one of its ends, i. e., its upper end as viewedin Fig. 5, is provided on its outer side with a narrowcircumferentially' extending rib or lug 36. Also the ring 35 adjacent tobut spaced circumferentially from its other end is provided on its outerside with a similar circularly extending rib'or lug 37. The retainerring 35 intermediate the ribs or lugs 36 and 37 is provided on its outerside with a third circularly extending rib or lug 38 which has a narrowtransversely extending slot 39 formed therein intermediate its ends. Theretainer ring 35 is positioned on the flange or rib 28 of the bobbinholder or case outside of the upstanding circular wall 29 thereof and ina position such that the rib 36 and the rib 37 pass into the openings 26and 25, respectively, in the end of the wall of the cup-shaped portion14 of the body and hence said ribs will line up with the groove 24 inthe wall of the'cup-shaped portion of the body. Also at such time therib'38 of the retainer ring passes into a third opening 40 formed in theend of the wall. of the cup-shaped portion 14 of the body and thus saidrib 38 will be aligned with the groove 24.

The retainer ring 35 on its fiat outer side has a cross slot 41formedtherein intermediate the ribs 36 and 33 and it will be seen thatany suitable narrow edged tool can be placed in the slot 41 and theretainer ring mo ed in a counterclockwise direction as seen in Fig. l tocause the ribs 36 and 37 to move in the groove 24 out of alignment withthe openings 26 and 25 and in the groove 24 into the dotted linepositions of Fig. 1. Also such movement of the retainer ring causes therib 38 to move in the groove 24out of alignment with the opening 40 andto the dotted line-position of Fig. l. Thus the retainer ring is heldagainst movement axially of the body by the ribs 36, 37Jand 38 beingengaged in the groove 24 of the body so that said ring acts to maintainthe flange 28 of the bobbin holder or case in engagement with thebearing shoulder 23 of the cup-shaped portion 14 of the body.

In order to prevent undesired circular dispiacement of the retainer ring35 relative to the body and to cause it to rotate with the body when ithas been thus mounted in operative position, the cup-shaped portion 14of the body is providedwith a double acting spring detent 42 which snapsinto the slot 379 of the rib '38 and holds the ring 35 against unwantedangular displacement relative to the body and causes the ring to rotatewith the body. However, when the operator desires to displace theretainer ring 35 angularly in a clockwise direction so as to align theribs 36, 37 and 38 with the openings 26, 25 and 40 in the end of thebody wall in order to remove the retainer ring and disassemble themechanism the pressure exerted on the retainer ring by the tool engagingin the slot 41 will readily overcome the holding action of the detent 42and permit this to be accomplished.

It will be seen that the operator can readily remove the bobbin case orholder from the body of the rotary hook mechanism merely by removing theretainer ring 35 which is a very simple operation requiring no skill andno special tool. Thus the operator will be able to correct any cloggingof the mechanism which might occur and can readily disassemble andreassemble the mechanism whenever the necessity of doing so occurs.

The bobbin for the lower thread which is mounted in the case or holderis indicated at 43 in Figs. 1 and 2. As stated in my copendingapplication Serial No. 246,43 7, filed September 13, 1951, this bobbinmay be formed of transparent material and the rotary hook mechanism maybe located beneath a transparent window in the hand hole cover of thebed plate, wherefore the operator can visually and readily ascertain thequantity of thread that is on the bobbin.

Although a preferred embodiment of the invention has been illustratedand described herein, it will be understood that the invention issusceptible of various modi fications and adaptations within the scopeor" the appended claims.

Having thus described my invention, I claim:

1. A rotary hook mechanism for a sewing machine comprising a rotary hookhaving a substantially cupshaped body provided internally with anannular bearing shoulder the plane of which is perpendicular to the axisof the hook, said body also being provided in outwardly spaced relationto said shoulder with an annular inwardly facing groove parallel to saidshoulder, the outer wall of said groove having a plurality of circularlyspaced openings therein communicating with said groove, a bobbin casemounted in said body and having an annular bearing flange supported bysaid shoulder, a fiat retainer ring mounted on said flange on the sidethereof remote to said shoulder, said ring being provided on itscircumferential edge with circularly spaced ribs which pass through saidopenings in the outer wall of said groove and into said groove wherebysaid ring may be angularly displaced relative to said body in onedirection to cause said ribs to move angularly in said groove relativeto said openings so as to underlie the outer wall of the groove andinterconnect said ring and said body, and means carried by the bobbincase and adapted to engage a stationary portion of the sewing machine tohold the bobbin case against rotation.

A rotary hook mechanism as defined in claim 1 ant wherein one of saidribs on said retaining ring is provided on its outer edge with a notchwhile said body is provided with a spring detent engaging said notchwhen said ribs have passed through said openings and are located in saidgroove by the angular displacement of said ring relative to said body insaid one direction whereby said ring and body are interconnected forunitary rotation.

3. A rotary hook mechanism as defined in claim 2 and wherein said ringis a split ring and one of said ribs is located at one end of said splitring, another of said ribs is located circularly inwardly of theopposite end of said ring, and the rib provided. with a notch is locatedintermediate said two first mentioned ribs, while said ring is providedwith a transversely extending tool receiving notch on its outer side.

References Cited in the file of this patent UNITED STATES PATENTS

